Recharging (or refilling) a dry chemical fire extinguisher is a task that should be left to qualified firefighters or fire extinguisher technicians. Dry chemical extinguishers are the most common on the market, however, and with the right equipment and materials, recharging one can be relatively easy.
Discharge the extinguisher fully. Do this by squeezing the handles together until all of the material is expelled and the canister feels lightweight.
Clean and check the extinguisher before recharging. Make sure that all parts are not clogged and are in working order. Use the water and plain soap to clean if necessary. Dry with the cloth.
Open the canister by unscrewing the top where the squeeze handles are located.
Pour the dry chemical refilling agent into the canister by using a funnel that is placed into the opening of the canister. Common dry chemicals include sodium bicarbonate, potassium bicarbonate or ammonium phosphate.
Continue to fill the canister with material until the predetermined level has been reached, either by the package details or the line drawn on the extinguisher canister itself.
Screw the top back onto the extinguisher and seal it tightly.
Attach the pressure machine to the fire extinguisher and start the machine up.
Pressurise the extinguisher until the dial reads in the green level or at least 100-150 psi (pounds per square inch); whichever the recharging material calls for.
Place the extinguisher back into the holder on the wall or cabinet properly. It is now ready to be used in case of emergencies.
Wear gloves to protect your hands from any possible spills from the dry chemicals. Even though they are dry, they can still potentially harm you. Latex examination gloves, gardening gloves, kitchen gloves, any kind will do. Local fire brigades often recharge fire extinguishers for free, check with yours to see if they offer this service.
Make sure to read the instructions on the specific material you are using and be aware of any safety measures which must be taken. Do not mix chemicals with each other if using more than one. Keep them in separate containers and close them fully before moving onto the next one. Mixing can cause undesirable effects though fumes, spills, adverse reactions, and more.